Resilient closure with a frangible skirt



Oct. 21, 1969 J. H. KARLAN RESILIENT CLOSURE WITH A FRANGIBLE SKIRT Filed Oct. 12, 1967 II A A C T B United States Patent Ofifice 3,473,685 Patented Oct. 21, 1969 3,473,685 RESILIENT CLOSURE WITH A FRANGIBLE SKIRT .lac H. Kai-Ian, 5992 Netherland Ave., Riverdale, N.Y. 10471 Filed Oct. 12, 1967, Ser. No. 674,967 Int. Cl. B6511 51/08, 55/08 US. Cl. 21541 Claims ABSTRACT OF THE DISCLOSURE A bottle closure of very flexible thermoset synthetic rubber has a very thin annular wall which inserts into the bottle and configurates to its interior surface to effect a tight seal. The lentgh of the wall is greater than its diameter and a flared end and a corrugation on the wall block passage of gas between the wall and the bottle.

This invention relates to bottle closures.

The general forms of bottle closures are familiar objects. These are bottle stoppers which are inserted and squeezed into the mouth of the bottle and bottle caps which snap over an external ring or bead on the bottle at or near its mouth. A third form of closure combines a stopper insert with a snap-on cap.

Typically, closures of this third form are made of thermoplastic material, usually polyethylene or polyvinylchloride. Though flexible to a degree, these closures are also relatively rigid because rigidity is needed in an inner head or ring on the cap which snaps over the external bead or ring at the mouth of the bottle. Some degree of rigidity is also needed in the cylindrical insert which enters the mouth of the bottle and squeezes against its internal walls to aid in holding it within the bottle. In essence then, the combined form of closure has borrowed its closure principles from the two general closure forms which it combines: it snaps-on over the outside of the bottle with a rigid bead or ring and it squeezes within the bottle with a rigid cylinder.

The present invention provides a substantial improvement over closures of this third general form.

It has been observed that prior closures are apt to require a considerable amount of force to press them down closed over a bottle but are also apt to pop up under large internal gas pressures within the bottle. One reason for the failure of these closures to hold securely is that their thermoplastic nature precludes making them suiliciently internally grooved so as to be able to grasp about a large external bead on the bottle. This is because the greater the undercut or internal groove, the more likely that it will permanently deform or crack when being removed from the mold that forms it.

Secondly, the more rigid the snap-on ring is made, the greater the pressure required to force it over an external bead on a bottle and the less appealing it will be to a potential user.

In the present invention, the closure principle of squeezing an insert within the cap is abandoned. Instead, the insert is made very flexible so as to configurate to the inside wall of the bottle and the internal gas pressure within the bottle is used to aid in maintaining the seal by pressing the insert against the bottle wall. Similarly, the rigid snap-on ring is rejected in the present invention in favor of an annular wall of flexible material with a relatively deep inward facing groove.

Other special features of the present invention relating to the bottle insert which contribute towards an effective seal are that the length of the insert is equal to or greater than its diameter, that the insert is flared out at its free end and that the insert has an annular corrugation thereon. It has been found that a thermoset material is most suitable for providing these configurations.

Advantageously, thermosetting synthetic rubber is appropriate for use. One such material well suited to providing these and other advantageous material characteristics described hereafter is Du Ponts Nordel.

Accordingly, it is an object of the present invention to provide a bottle closure capable of retaining relatively large pressures within the bottle while maintaining its seal.

Another object of this invention is to provide a bottle closure having a very flexible annular wall for insertion within a bottle which effectively seals by configurating to the inner walls of the bottle.

A further object of this invention is to provide a securely sealing bottle closure which requires relatively little force to affect closure.

An additional object of this invention is to provide a bottle closure of very flexible material which has relatively low gas permeability and which will not contaminate food products contained within the bottle.

Another object of this invention is to provide a bottle closure having an annular wall insert of a single desgin which will seal effectively standard bottles of different internal wall contours.

Yet another object of this invention is to provide a bottle closure which can be easily and conveniently separated from a skirt portion permanently sealed to the bottle and reused thereafter.

These and other objects and features of the present invention will be made fully clear from the following description taken in connection with the drawing in which:

FIGURE 1 is an isometric view of the bottle closure according to the present invention secured upon a bottle.

FIGURE 2 is a sectional view of the bottle closure and the bottle taken through the line 22 in FIG. 1.

FIGURE 3 is an isometric view of the upper portion of a bottle and the bottle closure with the closure removed from the bottle.

FIGURE 4 is a sectional view of the bottle closure shown in FIG. 3.

FIGURE 5 is a sectional view of a bottle closure and the top of a bottle with the closure aflixed to the bottle.

Referring now to the drawings, FIGURES 1 and 2 show a bottle closure, shown generally as 10, is secured over the top of a bottle 11. The closure 10 consists of a cap 12 having a base 13 from which a flexible outer hollow annular wall 14 depends. The outer annular wall 14 has a deep inward facing annular groove 15 which surrounds and substantially configurates to annular bead 16 at or near the mouth of the bottle 11. In this way the wall 14 will fit over and grasp about the annular head 16.

Also depending from the base 13 is a very flexible hollow annular inner wall 17, longer than the outer wall 14. The inner wall 17 extends from the base 13 a distance as great or greater than its inside diameter as measured at the base 13. Advantageously, the inner Wall 17 has a flared end portion 22 and a corrugation or ripple 18 thereon the purpose of each of which will be hereinafter explained. The inner wall 17 is the thinnest portion of the closure, the average thickness of the inner wall 17 being about one-half to one-third of the depth of the groove 15 or less. The wall 17 is substantially right circular from the base 13 to the start of the flared end 22, but has a tapered cross section from the base 13 to its flared end 22. The inward facing groove 15 is deep relative to prior closures, its depth being in the order of onefourth its width or more.

The outer wall 14 has a skirt 19 extending from it 3 which conforms to the curved or frusto-conical contour 21 of the portion of bottle 11 below its beaded mouth. The junction 20 of the skirt 19 and the outer wall 14 is purposely weakened therealong by scoring or perforating.

At several places around the outside of the closure, tabs 23 are positioned. These tabs 23 are integral with the cap 12 and have integral reinforcing arms 24 and reinforcing beads 25.

In FIGURES 1 and 2 the bottle closure is shown upon a bottle 11 as it might be affixed by a bottler. In this arrangement, the skirt 19, integral with and extending from the outer wall 14, has been spread to pass over the curved or frustoconical outer surface 21 of the bottle. When released, the skirt 19 will conform to and hug the bottle surface 21 tightly. As an aid, the skirt 19 can be glued to the outer surface 21 to permanently secure the skirt thereto. As shown, the bottle closure 10, is tightly secured to the bottle 11.

To release the closure, one need only press a sharp edge such as a knife or even ones fingernail at the weakened junction 20. The thermoset material employed will easily separate at the line of weakness. Thereafter, the closure 10 is removed from the bottle merely by pressing up on any one of the tabs 23. The thin, very flexible inner wall 17 will easily distort so that the closure can be removed from the bottle, leaving the skirt 19 behind as a permanent ring about the bottle surface 21. Thereafter the closure 10 can be repeatedly used on the same bottle or any other bottle of similar opening size.

FIGURES 3 and 4 show the closure 10 as used after separation from the skirt 19. This form of the closure 10, without the skirt 19, can also be furnished as such for all sorts of bottle applications. In this form, the closure 10 provides an easy to use, tight sealing bottle closure, which will retain gases within the bottle, such as the gases of carbonated liquids and will not contaminate the bottles contents.

The means by which the closure 10 affects a tight seal, even under conditions of high internal pressure, will now be explained with reference to FIGURES 4 and 5.

The thermoset nature of the material permits considerable distortion of the outer wall 14 when it is removed from the mold which forms it, without permanently deforming the outer wall 14 or causing it to crack. As a result, a deep inward facing annular groove 15 can be formed in the outer wall 14. This deep annular groove 15 will substantially cover and surround the outer annular bead 16 at the top of the bottle and hold the closure 10 securely to it.

The thin inner wall 17 is sufliciently flexible so that the flared end 22 can be inserted within the bottle. The flared end '22 provides a first sealing position within the bottle and acts as a gate to prevent gases within the bottle from passing between the inner wall 17 and the internal Wall 26 of the bottle.

The pressure within the bottle, in the space above the bottle contents is the same in all directions. This pressure, to whatever degree it may be found, presses the highly flexible inner wall 17 against the bottle wall 26 to configurate thereto. The greater the pressure within the bottle, such as large pressures which might occur from hot or highly carbonated contents, the more the highly flexible inner wall 17 is pressed against the bottle wall. Thus, the greater is the force which seals the bottle. The upward pressure against the base 13 is more than offset by the sideways pressure against the inner wall 17, which is long compared to its diameter.

Moreover, an interesting lever effect occurs at the base 13 as the pressure within the bottle builds up. The base 13 will tend to bulge up which causes the outer wall 14 to tend to rotate inwards towards the bottle to grasp with even greater force about the annular bead 16 on the bottle due to its flexibility.

The internal pressure within the bottle which contributes to tightly sealing the closure 10 is equalized on 4 both sides of the inner wall 17 when the tab 23 is lifted and the closure 10 is easily removed from the bottle.

The inner walls of the bottles near their top are typically of three forms: straight, beaded, or concave. The bottle closure 10 provides a second and upper sealing gate within the bottle which is operable with all three bottle forms. This is accomplished by the annular ripple or corrugation 18 on the inner Wall 17 between its ends. In the bottle form shown, the bottle wall 26 has a concave portion '27 near its top. The corrugation 18 extends from the inner wall 17 against this concave surface to affect a seal and is acted on by the pressure within the bottle.

By virtue of high flexibility without permanently deforming the material of which the closure 10 is formed, should permit formation of a highly flexible inner wall 17 and a deeply grooved flexible outer wall 14. Thermoset material, such as synthetic rubber has been found to provide these characteristics. In addition, the material advantageously should be of low permeability so that gas within the bottle will not pass through it and escape. Also. leaching of the sulphur from the elastomer material must be minimized so as not to contaminate the contents of the bottle. It has been found that Nordel synthetic rubber has a flexibility in the order of Durometer 60-70 (Shore t. manufactured by Du Pont satisfies all of these requirements.

While my invention has been described with reference to a specific embodiment, with and without a skirt portion, it should be understood that changes and modifications can be made to this embodiment by one skilled in the art without departing from the teachings of this invention. For example, while the inner wall 17 has been described as having a flare 22 at its free end, a small very flexible bead at the free end would be the virtual equivalent.

What is claimed is:

1. A closure for a receptacle having an external annular bead in the vicinity of the mouth thereof, comprising a base having a hollow flexible outer annular wall and a hollow inner annular wall of greater flexibility depending from said base, said outer annular wall having a flexibility of the order obtainable from flexible thermoset material, said inner annular wall having a flexibility sufficient to deform under the fluid pressure within said receptacle to configurate to the internal wall of said receptacle, said outer annular wall having an inward facing annular groove therein whereby said outer wall is adapted to surround and substantially cover said external bead on said receptacle, said inner annular wall being flared out at the end thereof remote from said base.

2. A closure in accordance with claim 1 in which the length of said inner wall from said base is at least equal to its inside diameter at said base.

3. A closure in accordance with claim 1 in which the depth of said inward facing groove is at least twice the average thickness of said inner wall.

4. A closure in accordance with claim 1 in which a skirt extends from said outer wall to hug about an outer surface portion of said receptacle below said external bead thereon, the junction of said skirt and said outer wall having a line of weakness therealong whereby said skirt and said outer wall are readily separable one from the other, said skirt having flexibility sufficient to configurate to the external wall of said receptacle.

5. A closure in accordance with claim 1 in which the ratio of the depth to the width of said inward facing groove is at least one to four.

6. A closure in accordance with claim 1 having an annular corrugation intermediate said end and said base.

7. A closure in accordance with claim 1 in which said closure is comprised of Nordel synthetic rubber material.

8. A closure for a receptacle having an external annular bead in the vicinity of the mouth thereof, comprising a base having a hollow flexible outer annular wall and a hollow inner annular wall of greater flexibility depending from said base, said outer annular Wall having a flexibility of the order obtainable from flexible thermoset material, said inner annular wall having a flexibility sufficient to deform under the fluid pressure within said receptacle to configurate to the internal wall of said receptacle, said outer annular wall having an inward facing groove therein whereby said outer Wall is adapted to surround and substantially cover said external head on said receptacle, the thickness of said inner Wall being substantially less than the depth of said inward facing groove, the length of said inner Wall from said base being at least equal to its inside diameter at said base.

9. A closure in accordance with claim 8 in which the length of said inner wall from said base is greater than its inside diameter at said base.

10. A closeure in accordance with claim 1 in which the flexibility of the closure material is in the order of Durorneter 60-70 (Shore).

References Cited UNITED STATES PATENTS GEORGE T. HALL, Primary Examiner US. Cl. X.R. 

